A quick, sharp and confident crack on the side of a narrow lipped bowl should do it. If you aren't that confident put the cracked egg onto a saucer or something similar before you place in the bowl and you should be able to remove any shell. Confidence is the key. Do you season your scrambled egg and add milk before scrambling?
Hold the egg gently but firmly in one hand - broad end against the heel of your hand, finger loosely around the narrower end. Tap the egg smartly against the side of your bowl or pan - be careful not to squeeze it or it will disintegrate. Move the egg into both hands and place your thumbs over the crack you have made. Hold the egg over the bowl or pan and very gently insert your thimb nails into the crack in the shell. Very gently but primly prise the two halves apart, the egg contents will frop ingo the pan / bowl and leave the shell behind. the trick is to be gentle but firm in handling your egg.
Sorry - for 'primly', read 'firmly' - not sure what happened there! Also, if it's easier. perform the initial 'crack' with two hands, but again, be firm but gentle, that's the secret with eggs.
quickness is the key - one day you may be as good as me and be able to have one in each hand, crack em at the same time and still end up with no shell! small talent, I know but one of which I am rightly proud!
I hear that a lot of chefs crak eggs by holding the egg in one palm, and 'slicing' it with a metal spatula/similar before transferring it to both hands and opening it up to let the insides out into the bowl. The slicing stroke must be a decisive one though, and I imagine there are issues with damaging the yolk. Still, if you're scrambling them there's not problem. Good for you, scrambling. The best way, in my humble opinion. Bob, you are indeed admirably adept. We salute you.
I just whack them firmly on the edge of a bowl or cup, then prise gently apart. If I want to keep the yolks whole, or separate out the yolks from the whites, I break the egg gently into my hand & let the whites trickle through into the bowl. This also helps catch any large pieces of broken shell. Good idea to wash hands first though!
This from a professional pastry cook, who has had to break eggs in large amounts[baked custards,etc] 30,40,60. .
The "confidence" advice is dead on.
and(and this is a confidence builder); eggshells sink to the bottom(in a few minutes)and will simply be left at the bottom of your dish/bowl.
P.S. If you're using your eggs for a baking recipe, try to let them get to room temperature first [they emulsify better]